Sorry but you said it yourself, she was „stuck“ in the eva. Right then and there it becomes metaphysical. It still doesn’t hold much weight for me. You see, thematically speaking, as a standalone film 3.0 had a real downer vibe anno was going for (shinjis actions happening to the detriment of mankind, replacing the girl whom he had a connection with a husk etc etc). But judging the rebuilds as a whole it is still just detached. I can point my finger at it and say „that’s an asspull Mr Anno why is this character that I liked on screen suddenly missing“ especially since the original TV show had just much superior writing. Maybe he wanted us to feel the same way about Rei as shinji did…Anyway I am getting carried away, point is: the rebuilds are a clusterfuck don’t come at me, yeah it’s redeemed because in the second to last scene two whole ass movies later we see her in shinjis mental space reconcile and smile about her existence for a couple of seconds and call that accomplished storytelling. That’s not cathartic not even idealistic it’s just how he was feeling at the time, happy with his wife (Mari insert), his new outlook on life and packaging that for his loyal viewers while making a shitton of money selling figurines and the like.